1 .. -*- coding: utf-8; mode: rst -*-
5 **************************************************************************
6 ioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDEV_G_STD, VIDIOC_SUBDEV_S_STD
7 **************************************************************************
12 VIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_STD - VIDIOC_SUBDEV_S_STD - Query or select the video standard of the current input
18 .. c:function:: int ioctl( int fd, VIDIOC_G_STD, v4l2_std_id *argp )
21 .. c:function:: int ioctl( int fd, VIDIOC_S_STD, const v4l2_std_id *argp )
24 .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_STD, v4l2_std_id *argp )
25 :name: VIDIOC_SUBDEV_G_STD
27 .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_STD, const v4l2_std_id *argp )
28 :name: VIDIOC_SUBDEV_S_STD
35 File descriptor returned by :ref:`open() <func-open>`.
38 Pointer to :c:type:`v4l2_std_id`.
44 To query and select the current video standard applications use the
45 :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctls which take a pointer to a
46 :ref:`v4l2_std_id <v4l2-std-id>` type as argument. :ref:`VIDIOC_G_STD <VIDIOC_G_STD>`
47 can return a single flag or a set of flags as in struct
48 :c:type:`v4l2_standard` field ``id``. The flags must be
49 unambiguous such that they appear in only one enumerated
50 struct :c:type:`v4l2_standard` structure.
52 :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one or more flags, being a write-only ioctl it
53 does not return the actual new standard as :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` does. When
54 no flags are given or the current input does not support the requested
55 standard the driver returns an ``EINVAL`` error code. When the standard set
56 is ambiguous drivers may return ``EINVAL`` or choose any of the requested
57 standards. If the current input or output does not support standard
58 video timings (e.g. if :ref:`VIDIOC_ENUMINPUT`
59 does not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is
66 On success 0 is returned, on error -1 and the ``errno`` variable is set
67 appropriately. The generic error codes are described at the
68 :ref:`Generic Error Codes <gen-errors>` chapter.
71 The :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` parameter was unsuitable.
74 Standard video timings are not supported for this input or output.